Setup one member MongoDB replica set - mongodb

I want to convert a standalone machine into one member replica set by configuring the same in /etc/init.d/mongodb.
I came across the below command to do the same:
sudo mongod --port 27017 --dbpath /srv/mongodb/db0 --replSet rs0
But it's not working out. My mongo is configured to run on autostart.
I ran the following command to stop the running instance before running with the --replSet option.
sudo service mongod stop
Both commands above run without any output/error but when I run rs.initiate(), I get the error below:
{
"ok" : 0,
"errmsg" : "not authorized on admin to execute command { replSetInitiate: undefined }",
"code" : 13
}
From the error message it looks like the issue seems to be of access. Can anybody give any pointers?
Also, if I succeed with above command, will I need to make any changes to /etc/mongod.conf or /etc/init.d/mongodb so that the instance continues to run as a one node replica?

Firstly: There are two ways of setting a mongod process's configuration; either (as in the command you found) as parameters on the command line, or in a configuration file mongod.conf. Your setup seems to be using a configuration file, so you need to put the replica set settings in the mongod.conf file, not on the command line.
Secondly: to run the rs.initiate() command on a system where authentication is enabled, as yours is, you must be authenticated as a user who has permission to run this command

Related

Unable to configure mongoDB

Im learning mongoDB and exploring its features, i try several commands when i run the terminal and mongod acts like does not care. It always starts the server even though i simply run for reading help.
Some commands that i run
mongod --help
mongod --port 5000
mongod --dbpath C:\myfolder\myproj\data\db
Everytime, no matter witch i run from the above commands it starts the server always even when searching for help. The port and path do not change also, it looks like it ingores everything other than the mongod in the terminal. Any help?
mongod starts the service, but when you close the terminal then also the service terminates.
However, usually you install mongod as a Service. See mongod.exe for details.
Maybe this package will help you: mongoDB-oneClick

MongoDB replication as a service on windows

I am trying to configure a replica set on windows as a service, means that even the PC will restart the mongod will run again automatically.
problem is that I run the mongod like this:
mongod --dbpath "C:\Program Files\MongoDB\Server\4.2\data" --logpath "C:\Program Files\MongoDB\Server\4.2\log\mongod.log" --port 27017 --storageEngine=wiredTiger --journal --replSet test_replica
And once I close the CMD running this command the service is killed. How do I run it correctly then?
Also, currenctly the service is navigating to the default cfg file but I see the replication there is marked with # (so the service is running as standalone). and when I try to add to replication the replSet: test_replica it won't start anymore.
You should put all your parameters into a configuration file. Then you can create the service like this:
mongod.exe --config c:\MongoDB\config\mongod.cfg --install
For a replica set you typically create several services, not just one. It is possible to run a replica set with just one member, however this is quite useless. Of course, when you create several services then each one needs his own config file (and also his own dbPath, port, etc.)
The next time your PC will boot, the mongo service should also start. Or start it manually with command net start <mongo service name>
You should install mongodb as windows service. Read the guide from the official documentation
Setting --replSet from command line or replication:replSetName in configuration file is not enough. Read this guide, in short: after mongodb process is started in replica set mode, you should run rs.initiate() in mongo shell.

How to execute 'service mongod start' using additional parameters in CentOS?

I unable to start MonogoDB service after adding users into admin db as well as my db.
I setup MonogoDB and started service using following command i.e.
service mongod start
Using command prompt, I added few users like dbOwner, clusterAdmin, readWrite, read roles base users. Along with that I also changed configuration from /etc/mongod.conf. in that file, I changed port number, IP addresses, dbPath, and security.authorization: enabled.
Then I restarted mongod service using following command.
service mongod restart
After ran this command, mongod service stopped successfully, but failed to start with only 'FAILED' message.
I tried execute following command i.e.
mongod --port 27123 --dbpath /path/to/db --auth
It is working.
Question: How to execute 'service mongod start' using additional parameters in CentOS?
MonogoDB: 3.4
OS: CentOS 7
I got solution i.e.
mongod --config /etc/mongod.conf
Referred: https://docs.mongodb.com/manual/reference/configuration-options/#use-the-configuration-file
It starts child process and also I can stop mongod service using service mongod stop command.
But I don't know whether it is correct or not.
I can't certify exactly where the script that "service" command uses on CentOS 7, but in Ubuntu 18.04 mongod service script file is in
/lib/systemd/system/mongod.service
There you can change the user who executes the process and add any parameters you want, like --auth.
Said that, if you ever executed mongod as root, some files on where you store the db data will have the owner as root, making the database fail to start as another user. The fix I found for that is to manually chown to mongodb:mongodb (or the user you want to use) all the files that are owned by root inside the database.
Hope this helps.
mongod.service file from mongodb github

Start Mongodb server in two modes parallely

I have installed mongo db in my local system, i am aware that at any point in time we can start the mongo using mongod service.
in normal mode which will run on port 27017
in rest API mode where we can query to collections and db's which normally runs on mongo port + 1000
i want to start both mode together, any help would be appreciated.
Thanks
Amit
You should add modify your mongod config file to enable http.
add following config line, see https://docs.mongodb.org/manual/reference/configuration-options/
net:
http:
enabled: true
or add parameter in the command line
mongod --httpinterface
You can start multiple instances of mongod. You just have to make sure that they're using different ports and different dbpaths.
To run two separate instances of mongod
mongod
This will start a mongod instance on port 27017 and use dbpath /data/db
Start another command prompt and type in
mongod --port 27018 --dbpath /data/db2
Just make sure that you have a folder named db2 inside your data folder in your c drive. That's where it stores the data.
Additionally, if you're on Node.js, the MongoDB Node.js driver provides a server method where you can start a mongod instance programatically.
var mongo = require("mongodb");
var server = new mongo.Server('localhost', 27017, { auto_reconnect : true} );
This will create a server in what you are calling the Rest API mode.
And then you can simply start mongod from command prompt specifying some other port and dbpath.
I'm not sure which we can start two instance of mondo or not!. but try this:
Run one of then through service mongod start and second one directly by running binary file (e.g. /usr/bin/mondodb). (also you can run both of them directly from CLI.)
In second mode, you most give appropriate parameter for mondo (e.g. path for config file). If you don't know how to give/pass parameters to mondo's binary file, see man mongodb or go and read /etc/init.d/mongod (in Debian based distributions), it give you useful information)
Unfortunately I don't have an installed mongoDB on my machine, so I can't give you exact commands.

getting an error when firing up mongodb in terminal [duplicate]

I'm getting the following error when I try to run "mongod" in the terminal. I've tried uninstalling, reinstalling, and restarting the machine. Any suggestions on how to get it working would be amazing.
ERROR:
dbpath (/data/db) does not exist.
Create this directory or give existing directory in --dbpath.
See http://dochub.mongodb.org/core/startingandstoppingmongo
Side note:
Node also stopped working on my machine around the same time that I got this error.
events.js:72
throw er; // Unhandled 'error' event
^
Error: failed to connect to [localhost:27017]
Any help would be much appreciated!
This should work to ensure that the directory is set up in the right place so that Mongo can find it:
sudo mkdir -p /data/db/
sudo chown `id -u` /data/db
You need to create the directory on root /data/db or set any other path with the following command :
mongod --dbpath /srv/mongodb/
See the example link
I solved the problem with :
sudo mongod --dbpath=/var/lib/mongodb and then mongo to access the mongodb Shell.
Change the user of the new data directory:
chown mongodb [rute_directory]
And try another time to start the mongo service
service mongod start
I solve the same problem with this.
Daemons (usually ending with d) are normally started as services. Starting the service (daemon) will allow mongodb to work as designed (without permission changes if integrates well with your distro). I start it using the service named mongodb instead of starting mongod directly--on distro with systemd enable on startup then run like:
sudo systemctl enable mongodb
sudo systemctl start mongodb
or, on distro with upstart (if you have /etc/init) or init (if you have /etc/init.d) ( https://www.tecmint.com/systemd-replaces-init-in-linux/ ) instead run:
sudo service mongodb enable
sudo service mongodb start
If you have a distro with rc ("run commands") such as Gentoo (settings in /etc/init.d) (https://forums.gentoo.org/viewtopic-t-854138-start-0.html) run:
rc-update add mongodb default
/etc/init.d/mongodb start
In a distro/version of FreeBSD which still has rc (check whether your version switched to systemd, otherwise see below):
add the following line to /etc/rc.conf:
mongod_enable="YES"
then:
sudo service mongod start
After starting the service, an unpriveleged user can use mongo, and each user will have separate data.
I also got the error that "The file /data/db doesn't exist" when I tried to save my file using the "mkdir -p /data/db" command(using both with and without sudo command). But later on one site, a person named Emil answered that the path "/data/db" no longer works on Mac, so use "~/data/db" instead
i.e., use the command
mkdir -p ~/data/db
instead of previous command.
Moreover, use
mongod --dbpath ~/data/db
to run mongod
It worked for me, hope it work for others too facing the same problem